阅读说明：本技术 一种成型金属零件的3d打印设备及方法 (3D printing equipment and method for forming metal parts ) 是由 刘洋 郑晓董 曹均 所新坤 李淑欣 于 2021-09-02 设计创作，主要内容包括：一种成型金属零件的3D打印设备及方法,包含成型缸,还包含激光熔覆系统、激光扫描系统和密封成型室；成型缸、喷嘴、送粉器和三自由度驱动机构布置在密封成型室内,喷嘴与送粉器通过导管相连通,喷嘴在三自由度驱动机构驱动作用下位置于或者远离成型缸内的金属成型区。成型方法包含：第一步、喷嘴置于成型缸的上方,为熔覆加工做好备；第二步、送粉器启动,喷嘴喷射加热熔化的金属粉末；第三步、激光熔覆每加工一层后,扫描使熔覆层的起伏表面及表面的飞溅颗粒熔化；第四步、在激光扫描完熔覆层后,再次进行激光熔覆加工,重复上述过程,直至工件完成加工。本发明可实现大尺寸金属零件的高效和高质量直接成型。(A3D printing device and method for forming metal parts comprises a forming cylinder, a laser cladding system, a laser scanning system and a sealed forming chamber; the forming cylinder, the nozzle, the powder feeder and the three-degree-of-freedom driving mechanism are arranged in the sealed forming chamber, the nozzle is communicated with the powder feeder through a guide pipe, and the nozzle is arranged in or far away from a metal forming area in the forming cylinder under the driving action of the three-degree-of-freedom driving mechanism. The molding method comprises the following steps: firstly, a nozzle is arranged above a forming cylinder and is prepared for cladding processing; secondly, starting a powder feeder, and spraying molten metal powder by a nozzle; thirdly, after each layer is processed through laser cladding, scanning to enable the undulating surface of the cladding layer and the splashing particles on the surface to be melted; and fourthly, after the laser scanning of the cladding layer is finished, carrying out laser cladding processing again, and repeating the process until the workpiece is processed. The invention can realize the high-efficiency and high-quality direct forming of large-size metal parts.)

1. The utility model provides a shaping metal parts's 3D printing apparatus, contains shaping jar (8), its characterized in that: the device also comprises a laser cladding system (A), a laser scanning system (B) and a sealed forming chamber (C);

the laser cladding system (A) comprises a laser (A15), a cladding spray head (A9), a powder feeder (A11) and a three-degree-of-freedom driving mechanism (A7);

the forming cylinder (8), the nozzle (A9), the powder feeder (A11) and the three-degree-of-freedom driving mechanism (A7) are arranged in a sealed forming chamber (C), a laser scanning system (B) is arranged on the outer side of the sealed forming chamber (C), the nozzle (A9) is communicated with the powder feeder (A11) through a guide pipe (A10), the laser (A15) is arranged outside the sealed forming chamber (C) and can provide laser beams into the nozzle (A9), the nozzle (A9) is arranged in or away from a metal forming area in the forming cylinder (8) under the driving action of the three-degree-of-freedom driving mechanism (A7), and the laser of the laser scanning system (A) can penetrate through the sealed forming chamber (C) to melt metal powder in the forming cylinder (8).

2. 3D printing device for forming metal parts according to claim 1, characterized in that: the laser scanning system (B) comprises a fiber laser (B1), a beam expanding collimating mirror (B2), a scanning galvanometer (B3), a window mirror (B4) and an optical lens (B5);

the beam expanding collimating lens (B2), the scanning galvanometer (B3), the window lens (B4) and the optical lens (B5) are all installed on a light path supporting plate (B6) at the top of the sealed forming chamber, the window lens (B4) and the optical lens (B5) are arranged above the forming cylinder (8), and laser of the fiber laser (B1) sequentially passes through the beam expanding collimating lens (B2), the scanning galvanometer (B3), the window lens (B4) and the optical lens (B5) and is emitted into the forming cylinder (8).

3. 3D printing device for forming metal parts according to claim 2, characterized in that: the laser (A15) is a carbon dioxide laser.

4. 3D printing device for forming metal parts according to claim 2, characterized in that: the three-degree-of-freedom driving mechanism (A7) comprises a vertical mechanism for controlling the nozzle (A9) to move up and down, a longitudinal mechanism (A72) for controlling the vertical mechanism to horizontally move longitudinally, and a transverse mechanism (A73) for controlling the longitudinal mechanism (A72) to horizontally move transversely.

5. 3D printing apparatus for forming metal parts according to claim 4, wherein: the transverse mechanism (A73) comprises a transverse lead screw pair, a transverse guide rail (A732), a base (A733) and a transverse motor;

the transverse motor is installed on the inner wall of the sealing forming chamber (C), the output end of the transverse motor is connected with a transverse lead screw (A730) of the transverse lead screw pair, the transverse lead screw (A730) is rotatably arranged on the inner wall of the sealing forming chamber (C), the transverse lead screw (A730) is arranged in parallel with a transverse guide rail (A732), the transverse guide rail (A732) is installed on the inner wall of the sealing forming chamber (C), and the base (A733) is connected with a nut of the transverse lead screw pair and is slidably arranged on the transverse guide rail (A732).

6. 3D printing device for forming metal parts according to claim 5, characterized in that: the longitudinal mechanism (A72) comprises a longitudinal lead screw pair, a longitudinal guide rail (A722), a bracket (A723), a longitudinal moving frame (A724) and a longitudinal motor;

a longitudinal lead screw (A721) of the longitudinal lead screw pair and a longitudinal guide rail (A722) are arranged on a support (A723) in parallel and are perpendicular to a transverse guide rail (A732), the support (A723) is fixed on a base (A733), a longitudinal motor is mounted on the support (A723), the output end of the longitudinal motor is connected with one end of the longitudinal lead screw (A721), the other end of the longitudinal lead screw (A721) is rotatably arranged on the support (A723), and a longitudinal moving frame (A724) is connected with a nut of the longitudinal lead screw pair and is slidably arranged on the longitudinal guide rail (A722).

7. 3D printing device for forming metal parts according to claim 6, characterized in that: the vertical mechanism (A71) comprises a vertical lead screw pair, a fixing plate (A712), a connecting plate (A713) and a vertical motor;

the fixing plate (A712) and the longitudinal moving frame (A724) are arranged at intervals and connected, two ends of a vertical lead screw (A711) of the vertical lead screw pair are rotatably arranged on the fixing plate (A712) and the longitudinal moving frame (A724), the vertical motor is installed on the fixing plate (A712), the output end of the vertical lead screw is connected with the vertical lead screw (A711), the connecting plate (A713) is connected with a nut of the vertical lead screw pair, and the nozzle (A9) is installed on the connecting plate (A713).

8. 3D printing device for forming metal parts according to claim 7, characterized in that: the thickness of the layer of metal deposited by the laser cladding system (A) in the metal forming area of the forming cylinder (8) is 1-3 mm.

9. A method of forming a metal part, comprising: comprises

Firstly, a nozzle (A9) is arranged above a forming cylinder (8) and is prepared for cladding processing;

secondly, starting a powder feeder (A11), feeding metal powder into the nozzle through a conduit (A10), melting the metal powder in the nozzle (A9) by a laser (A15) of the laser cladding system (A), spraying the heated and melted metal powder by the nozzle (A9), and dripping the metal powder on the forming substrate to form each bump;

thirdly, after each layer is processed by laser cladding, starting a laser scanning system (B) to scan to melt the fluctuated surface of the cladding layer and the splashed particles on the surface, and filling the bottom of the cladding channel;

and fourthly, after the laser scanning of the cladding layer is finished, carrying out laser cladding processing again, and repeating the process until the workpiece is processed.

10. A method of forming a metal part according to claim 9, wherein: the laser cladding system (A) is used for accumulating the thickness of the metal layer on the forming substrate of the forming cylinder (8) for 1-3mm each time.

Technical Field

The invention relates to 3D printing equipment and a forming method, in particular to 3D printing equipment and a method for forming metal parts.

Background

Selective Laser Melting (SLM) adopts high-energy-density laser beams to melt metal powder, and compact metal parts are formed by a layer-by-layer stacking method, and are increasingly applied in the fields of aerospace, molds, ocean engineering and the like. At present, manufacturers at home and abroad enlarge the forming size range of the SLM to be more than 650 multiplied by 650mm by adding a laser and a scanning galvanometer, and further expand the application range of the SLM technology and products. However, due to the interaction of the laser with the metal powder, a large amount of spatter (spatter mainly including molten material liquid and unmelted powder particles) is generated during the molding process, and the spatter falls on the surface of the molded article and is then mixed into the powder material as impurities, affecting the performance of the part. Currently, one of the methods to eliminate the impact of spatter is to reduce the production of spatter, but this involves very complex physical and process problems. On the other hand, the splash is blown away by large-flow air flow, but the method has not ideal effect when the large-size forming is carried out. There is therefore a need for a process which ensures the forming efficiency and reduces the negative effects of spatter.

Disclosure of Invention

The invention provides 3D printing equipment and a method for forming metal parts, aiming at overcoming the defects of the prior art. The 3D printing equipment and the forming method are high in cladding efficiency, and the surface quality of the formed part is good.

A3D printing device for forming metal parts comprises a forming cylinder, a laser cladding system, a laser scanning system and a sealed forming chamber; the laser cladding system comprises a laser, a cladding nozzle, a powder feeder and a three-degree-of-freedom driving mechanism; the forming cylinder, the nozzle, the powder feeder and the three-degree-of-freedom driving mechanism are arranged in the sealed forming chamber, a laser scanning system is arranged on the outer side of the sealed forming chamber, the nozzle is communicated with the powder feeder through a guide pipe, the laser is arranged outside the sealed forming chamber and can provide laser beams into the nozzle, the nozzle is arranged in or away from a metal forming area in the forming cylinder under the driving action of the three-degree-of-freedom driving mechanism, and the laser of the laser scanning system can penetrate through the metal powder in the sealed forming chamber to melt the metal powder in the forming cylinder.

A method of forming a metal part, comprising:

firstly, a nozzle is arranged above a forming cylinder and is prepared for cladding processing;

secondly, starting a powder feeder, feeding metal powder into a nozzle through a guide pipe, melting the metal powder in the nozzle by a laser of a laser cladding system, spraying the heated and melted metal powder from the nozzle, and dripping the metal powder on a forming substrate to form each protrusion;

thirdly, after each layer is processed by laser cladding, starting a laser scanning system to scan to melt the fluctuated surface of the cladding layer and the splashed particles on the surface, and filling the bottom of the cladding channel;

and fourthly, after the laser scanning of the cladding layer is finished, carrying out laser cladding processing again, and repeating the process until the workpiece is processed.

Compared with the prior art, the invention has the beneficial effects that:

according to the 3D printing equipment, the laser cladding equipment and the laser scanning system are designed, the laser cladding system is used for cladding and processing metal materials, the laser scanning system is used for melting cladding layer materials, and then secondary melting is carried out, the laser cladding system is used for improving the 3D printing efficiency of large-size metal parts, the laser scanning technology is used for improving the roughness of the cladding surface and removing impurities (splashing particles, spheroidization and the like) on the surface, and the surface precision and the size precision of the 3D printed metal parts are improved.

According to the method for molding the large-size metal part, the metal powder is firstly cladded by the laser, and the laser cladding efficiency is high, so that the laser scanning system is adopted to scan the cladded surface after the laser cladding, and the surface roughness is reduced. Because laser cladding is a processing mode of coaxial powder feeding, less splashes are generated in the forming process, and in the Scanning (SLM) link of a laser scanning system, less splashes are generated due to the fact that the laser scanning cladding layer is adopted, so that the influence of the splashes on the performance of a formed part is reduced to the maximum extent. By using the forming method of the invention, the steps are alternately and repeatedly carried out, so that the workpiece can be processed at a super high speed, the processing time of the workpiece is reduced, the internal structure is ensured to be stable, and better precision and surface quality can be obtained. Can realize the high-efficiency and high-quality direct forming of large-size metal parts.

The technical scheme of the invention is further explained by combining the drawings and the embodiment:

drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a top view of the three-degree-of-freedom driving mechanism;

FIG. 3 is a schematic diagram of a three-degree-of-freedom driving mechanism driving a nozzle to move away from a forming cylinder for laser scanning after a layer of metal powder is processed by laser cladding;

fig. 4 is a schematic flow chart of a work flow of forming a metal part by using a 3D printing device.

Detailed Description

As shown in fig. 1-2, the 3D printing apparatus for forming metal parts of the present embodiment includes a forming cylinder 8, a laser cladding system a, a laser scanning system B, and a sealed forming chamber C;

the laser cladding system A comprises a laser A15, a cladding spray head A9, a powder feeder A11 and a three-degree-of-freedom driving mechanism A7; the forming cylinder 8, the nozzle A9, the powder feeder A11 and the three-degree-of-freedom driving mechanism A7 are arranged in a sealed forming chamber C, a laser scanning system B is arranged on the outer side of the sealed forming chamber C, the nozzle A9 is communicated with the powder feeder A11 through a guide pipe A10, the laser A15 is arranged outside the sealed forming chamber C and can provide laser beams into the nozzle A9, the nozzle A9 is arranged in or far away from a metal forming area in the forming cylinder 8 under the driving action of the three-degree-of-freedom driving mechanism A7, and laser of the laser scanning system A can penetrate through the sealed forming chamber C to melt metal powder in the forming cylinder 8.

According to the technical scheme of the embodiment, laser cladding and laser scanning processing are integrated, the structure is stable and reliable, the forming process is simple and convenient, and direct forming of metal materials can be realized. The laser cladding system A and the laser scanning system B are connected with the central control system, the three-degree-of-freedom driving mechanism A7 is controlled, and the nozzle A9 is controlled to move up and down, left and right and back and forth, so that the metal powder is processed by laser cladding and the metal powder is scanned and melted by laser.

Typically, laser a15 is a carbon dioxide laser.

Further, the laser scanning system B comprises a fiber laser B1, a beam expanding collimating mirror B2, a scanning galvanometer B3, a window mirror B4 and an optical lens B5; the beam expanding collimating lens B2, the scanning galvanometer B3, the window lens B4 and the optical lens B5 are all installed on an optical path supporting plate B6 at the top of the sealed forming chamber, the window lens B4 and the optical lens B5 are arranged above the forming cylinder 8, and laser of the optical fiber laser B1 sequentially passes through the beam expanding collimating lens B2, the scanning galvanometer B3, the window lens B4 and the optical lens B5 and is emitted into the forming cylinder 8.

In the scheme, the window mirrors B4 are arranged at the top of the sealed forming chamber C in an array manner, so that the sealed forming chamber C and the laser scanning system B are isolated, and the influence of smoke dust generated in the processing process on the laser scanning system B is prevented; the deflected light beams passing through the beam expanding collimating lens B2 (beam expanding lens and collimating lens) are transmitted into the sealed forming chamber C through the window lens B4, the cladding layer is melted, the undulating surface of the cladding layer and impurities (such as splashing, spheroidizing and the like) are melted again, the undulating surface of the cladding layer and splashing particles on the undulating surface are melted, the bottom of a cladding channel is filled, the surface roughness of a workpiece is reduced, and the surface quality is improved.

Further, as shown in fig. 1-3, the three-degree-of-freedom driving mechanism a7 for controlling the movement of the nozzle a9 is electrically driven, and the three-degree-of-freedom driving mechanism a7 includes a vertical mechanism for controlling the nozzle a9 to move up and down, a longitudinal mechanism a72 for controlling the vertical mechanism to move horizontally and longitudinally, and a transverse mechanism a73 for controlling the longitudinal mechanism a72 to move horizontally and transversely.

Further, the transverse mechanism a73 comprises a transverse screw pair, a transverse guide rail a732, a base a733 and a transverse motor; the transverse motor is installed on the inner wall of the sealing forming chamber C, the output end of the transverse motor is connected with a transverse lead screw A730 of the transverse lead screw pair, the transverse lead screw A730 is rotatably arranged on the inner wall of the sealing forming chamber C, the transverse lead screw A730 is arranged in parallel with a transverse guide rail A732, the transverse guide rail A732 is installed on the inner wall of the sealing forming chamber C, and the base A733 is connected with a nut of the transverse lead screw pair and is slidably arranged on the transverse guide rail A732. Based on the principle of a screw rod and a nut, a transverse motor is started to drive a transverse screw rod A730 to rotate, so that the base A730 reciprocates on a transverse guide rail A732, a longitudinal mechanism A72 arranged on the base A is driven to reciprocate, the horizontal transverse movement of a nozzle A9 is realized, and metal cladding and laser scanning melting are conveniently completed.

The longitudinal mechanism A72 comprises a longitudinal lead screw pair, a longitudinal guide rail A722, a bracket A723, a longitudinal moving frame A724 and a longitudinal motor; the longitudinal lead screw A721 of the longitudinal lead screw pair is arranged on a support A723 in parallel with a longitudinal guide rail A722 and is perpendicular to a transverse guide rail A732, the support A723 is fixed on a base A733, a longitudinal motor is arranged on the support A723, the output end of the longitudinal motor is connected with one end of the longitudinal lead screw A721, the other end of the longitudinal lead screw A721 is rotatably arranged on the support A723, and a longitudinal moving frame A724 is connected with a nut of the longitudinal lead screw pair and is slidably arranged on the longitudinal guide rail A722. Based on the principle of a screw rod and a nut, a longitudinal motor is started to drive a longitudinal screw rod A721 to rotate, so that the longitudinal moving frame A724 can reciprocate on a longitudinal guide rail A722 to drive a vertical mechanism arranged on the longitudinal moving frame A to reciprocate, the horizontal longitudinal movement of a nozzle A9 is realized, and the metal cladding is conveniently completed.

The vertical mechanism A71 comprises a vertical lead screw pair, a fixing plate A712, a connecting plate A713 and a vertical motor; the fixing plate A712 and the longitudinal moving frame A724 are arranged at intervals and connected, two ends of a vertical lead screw A711 of the vertical lead screw pair are rotatably arranged on the fixing plate A712 and the longitudinal moving frame A724, the vertical motor is installed on the fixing plate A712, the output end of the vertical motor is connected with the vertical lead screw A711, the connecting plate A713 is connected with a nut of the vertical lead screw pair, and the nozzle A9 is installed on the connecting plate A713. Based on the principle of a screw rod and a nut, the vertical motor is started to drive the vertical screw rod 711 to rotate, so that the connecting plate A713 is driven to reciprocate up and down, the nozzle A9 arranged on the connecting plate A is driven to reciprocate up and down, the vertical movement of the nozzle A9 is realized, and metal cladding is conveniently completed. Preferably, the transverse motor, the longitudinal motor and the vertical motor are all servo motors, and a 110ZFMA1-0D80CBNM model servo motor manufactured by Zhongzhi electric Nanjing Limited company can be selected.

In the above, the thickness of the layer of metal deposited by the laser cladding system a in the metal forming area of the forming cylinder 8 is controlled by the central control system to be 1-3 mm.

As shown in fig. 1 to 4, in another embodiment, there is also provided a method for forming a metal part using the above 3D printing apparatus:

firstly, a nozzle A9 is arranged above a forming cylinder 8 and is prepared for cladding processing;

secondly, starting a powder feeder A11, feeding metal powder into the nozzle through a conduit A10, melting the metal powder in the nozzle A9 by a laser A15 of the laser cladding system A, and spraying the heated and melted metal powder out of the nozzle A9 to drop on the forming substrate to form each protrusion;

thirdly, after each layer is processed by laser cladding, starting a laser scanning system B to scan to melt the fluctuated surface of the cladding layer and the splashed particles on the surface, and filling the bottom of the cladding channel;

and fourthly, after the laser scanning of the cladding layer is finished, carrying out laser cladding processing again, and repeating the process until the workpiece is processed.

When the equipment is operated, the nozzle A9 moves to the rightmost side of the forming cylinder 8 through the transverse mechanism A73 and the longitudinal mechanism A72, the vertical mechanism is used for adjusting, then the powder feeder A11 is started, metal powder enters the nozzle A9 through a guide pipe A10 (such as a soft guide pipe), a carbon dioxide laser of the laser cladding system A melts the metal powder in the nozzle A9 through coaxial red light to be accumulated on a forming substrate, after a first layer is clad, the powder feeder A11 and the laser A15 (such as a carbon dioxide laser) stop working, and the transverse mechanism is driven to enable the nozzle A9 to move to the leftmost side of the forming cylinder 8 to enter a standby state.

And the laser scanning system B performs secondary processing, controls the optical fiber laser beam to scan the cladding layer, melts the surface of the cladding layer, and remelts the fluctuant surface of the cladding layer and impurities (such as splashing, spheroidization and the like) so that the fluctuant surface of the cladding layer and the splashed particles on the fluctuant surface are melted, and fills the bottom of the cladding channel, thereby reducing the surface roughness of the workpiece and improving the surface quality. And after the laser scans the cladding layer, carrying out laser cladding processing again, and repeating the processes until the workpiece is processed.

Because laser cladding is a processing mode of coaxial powder feeding, less splashes are generated in the forming process, and in the link of selective laser melting (laser scanning system B), less splashes are generated due to the fact that the cladding layer is scanned by laser, so that the influence of the splashes on the performance of a formed part is reduced to the maximum extent. Optionally, the laser cladding system a stacks metal layers on the forming substrate of the forming cylinder 8 each time with a thickness of 1-3 mm.

The present invention is not limited to the above embodiments, and those skilled in the art can make various changes and modifications without departing from the scope of the invention.